Waste Management Work on Emerging Compounds
The Division of Waste Management’s (DWM) per- and polyfluoroalkyl substance strategy includes several key elements. From community engagement and outreach to working with state and local partners as PFAS compounds are detected, the division focuses on the impacts that these compounds have on the people and environment. There are new and emerging compounds beyond PFAS, such as 1,4-dioxane, and division staff continue to work with permitted facilities to identify and provide technical solutions when such compounds are found based on relevant science and research.
The first key element of the strategy includes continued engagement with communities across North Carolina regarding PFAS. The Division of Waste Management has worked diligently across the state from the Piedmont to the Coastal Plain to engage communities on this important subject. The division's plan for continued engagement with communities includes planning for and participating in public information sessions regarding PFAS, disseminating information through DEQ’s website and active participation in upcoming conferences regarding this important subject. The DWM will also continue to support local health departments by providing assistance on environmental sampling for PFAS and to be a resource in conjunction with state's Department of Health and Human Services (DHHS) on health effects.
The second key element included in DWM’s PFAS strategy includes evaluating current sites within DWM’s inventory where potential PFAS impacts may exist. DWM’s strategy includes continued evaluation of Municipal Solid Waste Landfill leachate for PFAS, reviewing current RCRA sites with closure permits for potential use of AFFF fire-fighting foam and continued coordination with Department of Defense facilities regarding PFAS areas of concern. This element will also include coordination with stakeholders to obtain sampling data related to PFAS to ensure protection of receptors to include private well users.
Division of Waste Management PFAS Data by Concentration and PFAS Group as presented during the Secretaries Science Advisory Board Dec. 7, 2020, meeting.
The third element of DWM’s PFAS strategy includes continued focus on evaluating treatment technologies that are available for private well water treatment to include Granular Activated Carbon (GAC) and Reverse Osmosis (RO) systems. The DWM plans to sample the newly installed reverse osmosis systems that are being installed around the Chemours' Fayetteville Works plant while also finishing the granular activated carbon pilot testing program. The DWM’s testing will continue to provide critical information on the effectiveness of these systems to ensure safe private well water supplies are being provided to the public.
The final element of DWM’s PFAS strategy includes continued and expansion of staff knowledge base to make informed decisions on PFAS. By sending division staff to local and national conferences on PFAS-related issues, staff will expand their knowledge base. They will also maintain productive relationships with other agencies like NCDHHS and the N.C. Department of Agriculture and Consumer Services to further knowledge on this subject.
Summary of the NC Collective Study: North Carolina Emerging Compounds in Landfill Leachate and Estimated Influence on Wastewater Treatment Plant Facilities
The Division of Waste Management engaged nine municipal solid waste landfill across the state to evaluate the presence of emerging compounds in landfill leachate and the associated influence on municipal wastewater treatment plants that receive the leachate.
The study was conducted by an environmental consultant hired by the landfill operators, and included the collection of leachate samples from four landfills in the Cape Fear River Basin and five landfills across the remainder of the state. The leachate from these facilities was sampled for PFAS (Per- and polyfluoroalkyl substances), 1, 4-Dioxane and, at one location, PFPrOPrA (GenX).
PFAS and 1,4-Dioxane are contaminants of emerging concern and are being evaluated by DEQ across a variety of media within North Carolina. PFAS and 1,4-Dioxane are found in a wide range of products and wastes. For example, PFAS can be found in stain- and water-repellent fabrics and carpeting, nonstick products, firefighting foam, and industrial wastes, while 1,4-Dioxane can be found in cleaning products, shampoo and body wash, and industrial wastes.
The Division of Waste Management reached out to landfill operators after reviewing the current body of data as it relates to the presence of emerging compounds in landfill leachate. One of the data sources noted by DEQ was the Michigan Waste & Recycling Association study that was completed in March 2019. The Michigan study analyzed for PFOS and PFOA in landfill leachate and included 32 municipal solid waste landfills and the leachate influence on wastewater treatment plants influent concentrations in the State of Michigan. Some of the study conclusions noted that municipal solid waste landfill leachate provides a relatively minor contribution to the overall PFOA and PFOS concentrations in most wastewater treatment plant influent, and non‐leachate sources contribute greater mass.
Between July and September 2019, DEQ required that wastewater treatment plants in the Cape Fear River basin with pretreatment programs collect influent samples for PFAS and 1,4‐Dioxane analysis (including four wastewater treatment plants that receive leachate from municipal solid waste landfills in the NC Collective Study).
For the wastewater treatment plants that receive leachate from landfills in the NC Collective Study, DEQ concluded that the PFOS, PFOA and 1,4‐Dioxane concentrations for these wastewater treatment plants would not cause levels at downstream public water supply intakes that exceed the respective EPA Drinking Water Health Advisory Levels. The NC Collective Study concludes that landfill leachate represents minor contribution of PFOS, PFOA and 1,4‐Dioxane mass to overall wastewater treatment plants influent mass for these compounds. It also concludes that non-leachate sources contribute significantly more mass. Furthermore, the report emphasizes that municipal solid waste landfills and wastewater treatment plants receive PFAS and 1,4‐Dioxane in the form of consumer products and other wastes, but are not the producers or original sources.
The report recommends continued work towards PFAS and 1,4‐Dioxane source reduction solutions as well as collaboration between the solid waste and wastewater treatment industries, DEQ and the scientific community to identify best management practices and other solutions for safe management of wastes generated by North Carolina communities. Others, including a Collaboratory of North Carolina universities, are also studying the issues and collecting samples at landfills and wastewater treatment plants across the state. Their results are expected in 2021, and will further inform DEQ’s response to these emerging contaminants in North Carolina’s surface waters.